关键词: 盾构隧道, 近接下穿； 精细化管控； 微沉降控制

Abstract: To effectively control the settlement of the existing Wuhan metro line 2 induced by neighboring shield tunneling of metro line 7 in the third terrace of Yangtze river, the settlement control during the whole process of the shield tunneling is studied and analyzed. According to the test results of shield tunneling technology and construction scheme optimization, the piperoof advance support is cancelled, and the compensatory grouting behind tunnel wall, segment tensioning and reinforcement, and joint sealing are conducted to metro line 2. Meanwhile, the shield tunneling parameters are precisely controlled, highaccuracy monitoring informationized construction and clay shock method are adopted. The monitoring and practical results show that a micro settlement less than 1 mm is achieved, indicating the feasibility of the recommended methods.

Key words: shield tunnel, neighboring underneath crossing, fine control, micro settlement control